Conformally flat black holes in Poincar\'e gauge theory

Understand

General criteria for the existence of conformally flat Riemannian solutions in 3D Poincar\'e gauge theory without matter are formulated.

• Using these criteria, we show that the Oliva-Tempo-Troncoso black hole, a solution of the Bergshoeff-Hohm-Town\-send gravity, is also an exact vacuum solution of the Poincar\'e gauge theory.
• The related conserved charges, calculated from the Hamiltonian boundary term, are shown to satisfy the first law of black hole thermodynamics.
• The form of the boundary term is verified by using the covariant Hamiltonian approach.